NAME
VGLBitmapAllocateBits
,
VGLBitmapCopy
,
VGLBitmapCreate
,
VGLBitmapDestroy
,
VGLBitmapPutChar
,
VGLBitmapString
,
VGLBlankDisplay
, VGLBox
,
VGLCheckSwitch
, VGLClear
,
VGLEllipse
, VGLEnd
,
VGLFilledBox
,
VGLFilledEllipse
, VGLGetXY
,
VGLInit
, VGLLine
,
VGLKeyboardInit
,
VGLKeyboardEnd
,
VGLKeyboardGetCh
,
VGLMouseInit
, VGLMouseMode
,
VGLMouseSetImage
,
VGLMouseSetStdImage
,
VGLMouseStatus
,
VGLPanScreen
, VGLSetBorder
,
VGLSetPalette
,
VGLSetPaletteIndex
,
VGLSetVScreenSize
, VGLSetXY
,
VGLTextSetFontFile
—
Video Graphics Library
functions
LIBRARY
library “libvgl”
SYNOPSIS
#include
<machine/console.h>
#include <vgl.h>
int
VGLInit
(int
mode);
void
VGLEnd
(void);
void
VGLCheckSwitch
(void);
int
VGLTextSetFontFile
(char
*filename);
int
VGLKeyboardInit
(int
code);
void
VGLKeyboardEnd
(void);
int
VGLKeyboardGetCh
(void);
int
VGLMouseInit
(int
mode);
void
VGLMouseMode
(int
mode);
int
VGLMouseStatus
(int
*x, int *y,
char *buttons);
void
VGLMouseSetImage
(VGLBitmap
*AndMask, VGLBitmap
*OrMask);
void
VGLMouseSetStdImage
(void);
byte
VGLGetXY
(VGLBitmap
*object, int x,
int y);
void
VGLSetXY
(VGLBitmap
*object, int x,
int y,
byte color);
void
VGLLine
(VGLBitmap
*object, int x1,
int y1,
int x2,
int y2,
byte color);
void
VGLBox
(VGLBitmap
*object, int x1,
int y1,
int x2,
int y2,
byte color);
void
VGLFilledBox
(VGLBitmap
*object, int x1,
int y1,
int x2,
int y2,
byte color);
void
VGLEllipse
(VGLBitmap
*object, int xc,
int yc,
int a,
int b,
byte color);
void
VGLFilledEllipse
(VGLBitmap
*object, int xc,
int yc,
int a,
int b,
byte color);
VGLBitmap *
VGLBitmapCreate
(int
type, int xsize,
int ysize,
byte *bits);
void
VGLBitmapDestroy
(VGLBitmap
*object);
int
VGLBitmapAllocateBits
(VGLBitmap
*object);
int
VGLBitmapCopy
(VGLBitmap
*src, int srcx,
int srcy,
VGLBitmap *dst,
int dstx,
int dsty,
int width,
int hight);
void
VGLBitmapPutChar
(VGLBitmap
*Object, int x,
int y,
byte ch,
byte fgcol,
byte bgcol,
int fill,
int dir);
void
VGLBitmapString
(VGLBitmap
*Object, int x,
int y,
char *str,
byte fgcol,
byte bgcol,
int fill,
int dir);
void
VGLClear
(VGLBitmap
*object, byte
color);
void
VGLSetPalette
(byte
*red, byte *green,
byte *blue);
void
VGLSetPaletteIndex
(byte
color, byte red,
byte green,
byte blue);
void
VGLSetBorder
(byte
color);
int
VGLSetVScreenSize
(VGLBitmap
*object, int
vxsize, int
vysize);
int
VGLPanScreen
(VGLBitmap
*object, int x,
int y);
void
VGLBlankDisplay
(int
blank);
DESCRIPTION
Libvgl
is a library that enables the programmer access
to the graphics modes supported by the console driver
(syscons(4)). The library takes care of programming the actual video
hardware, and provides a number of simple functions to do various graphic
operations. There is also support for a mouse via the standard mouse system in
DragonFly, see
mouse(4), including the ability to transparently have a mouse pointer
superimposed on the graphic image currently being worked on. The library takes
care of screen switching by storing the current image in memory before
switching to another virtual console, and restoring when the user switches
back. This allows several graphic applications at once, but on different
virtual consoles.
Below is a short description of the various functions:
VGLInit
()
initialize the library and set up the graphic mode
mode.
VGLEnd
()
terminate graphic mode, and restore the screenmode that was active before
VGLInit
() was called.
VGLCheckSwitch
()
if the program goes into longer periods of processing without doing any
graphics output, calling this function occasionally will allow the system to
switch screens.
VGLTextSetFontFile
()
instruct the char/string functions to use the font in file
filename instead of the builtin font.
VGLKeyboardInit
()
set up the keyboard in the “raw” I/O mode and specify the key
code to be used. code must be
VGL_XLATEKEYS
, VGL_CODEKEYS
,
or VGL_RAWKEYS
. When
VGL_XLATEKEYS
is specified, the keyboard translate
the raw keyboard scan code into a character code. If
VGL_RAWKEYS
is used, the raw keyboard scan code is
read as is. VGL_CODEKEYS
is the intermediate key
code; each key is assigned a unique code whereas more than one raw scan code
may be generated when a key is pressed.
VGLKeyboardEnd
()
when you have finished using the keyboard, call this function.
VGLKeyboardGetCh
()
read one byte from the keyboard. As the keyboard I/O is in the
“raw” input mode, the function will not block even if there is
no input data, and returns 0.
VGLMouseInit
()
initialize the mouse. The optional on-screen mouse pointer is shown if the
argument is VGL_MOUSESHOW
.
VGLMouseMode
()
either shows the mouse pointer if the argument is
VGL_MOUSESHOW
, or hides the mouse pointer if the
argument is VGL_MOUSEHIDE
.
VGLMouseStatus
()
returns the current mouse pointer coordinates and button state in
x, y, buttons. The return value
reflects if the mouse pointer is currently shown on screen or not.
VGLMouseSetImage
()
with this function it is possible to change the image of the mouse pointer
on screen.
VGLMouseSetStdImage
()
this function restores the mouse pointer to the standard arrow.
VGLGetXY
()
retrieves the color of the pixel located at x,
y, coordinates of the object
argument, and returns it as a byte value.
VGLSetXY
()
sets the color of the pixel located at x,
y, coordinates of the object
argument to color byte value.
VGLLine
()
draw a line from x1, y1 to
x2, y2 in color
color.
VGLBox
()
draw a box with upper left hand corner at x1,
y1 and lower right hand corner at
x2, y2 in color
color.
VGLFilledBox
()
draw a filled (solid) box with upper left hand corner at
x1, y1 and lower right hand
corner at x2, y2 in color
color.
VGLEllipse
()
draw an ellipse centered at xc,
yc make it a pixels wide, and
b pixels high in color
color.
VGLFilledEllipse
()
draw a filled (solid) ellipse centered at xc,
yc make it a pixels wide, and
b pixels high in color
color.
VGLBitmapCreate
()
create a bitmap object and initialize it with the specified values and bit
data. type must be MEMBUF
for
the in-memory bitmap. bits may be NULL so that bitmap
data may be associated later.
There also is a macro,
VGLBITMAP_INITIALIZER
(type,
xsize, ysize,
bits) to initialize a statically declared bitmap
object.
VGLBitmapDestroy
()
free the bitmap data and the bitmap object.
VGLBitmapAllocateBits
()
allocate a bit data buffer for the specified object.
VGLBitmapCopy
()
copy a rectangle of pixels from bitmap src upper left
hand corner at srcx, srcy to
bitmap dst at dstx,
dsty of the size width,
height.
VGLBitmapPutChar
()
write the character ch at position
x, y in foreground color
fgcol. If fill is != 0, use the
color bgcol as background otherwise the background is
transparent. The character is drawn in the direction specified by the
argument dir.
VGLBitmapString
()
write the string str at position
x, y in foreground color
fgcol. If fill is != 0, use the
color bgcol as background otherwise the background is
transparent. The string is drawn in the direction specified by the argument
dir.
VGLClear
()
clears the entire bitmap to color color.
VGLSetPalette
()
this function sets the palette used, the arguments
red, green,
blue should point to byte arrays of 256 positions
each.
VGLSetPaletteIndex
()
set the palette index color to the specified RGB
value.
VGLSetBorder
()
set the border color to color color.
VGLSetVScreenSize
()
change the virtual screen size of the display. Note that this function must
be called when our vty is in the foreground. And
object must be VGLDisplay.
Passing an in-memory bitmap to this function results in error.
The desired virtual screen width may not be achievable because of the video card hardware. In such case the video driver (and underlaying video BIOS) may choose the next largest values. Always examine object->VXsize and VYsize after calling this function, in order to see how the virtual screen is actually set up.
In order to set up the largest possible virtual screen, you may call this function with arbitrary large values.
VGLSetVScreenSize(10000,
10000);
VGLPanScreen
()
change the origin of the displayed screen in the virtual screen. Note that
this function must be called when our vty is in the foreground.
object must be VGLDisplay.
Passing an in-memory bitmap to this function results in error.
VGLBlankDisplay
()
blank the display if the argument blank ≠ 0.
This can be done to shut off the screen during display updates that the user
should first see when it's done.
Program termination and signal processing
It is important to call VGLEnd
() before
terminating the program. Care must be taken if you install signal handlers
and try to call VGLEnd
() and
exit(3) to end the program. If a signal is caught while the program
is inside libvgl
functions,
VGLEnd
() may not be able to properly restore the
graphics hardware.
The recommended way to handle signals and program
termination is to have a flag to indicate signal's delivery. Your signal
handlers set this flag but do not terminate the program immediately. The
main part of the program checks the flag to see if it is supposed to
terminate, and calls
VGLEnd
()
and exit(3) if the flag is set.
Note that
VGLInit
()
installs its internal signal handlers for SIGINT
,
SIGTERM
, SIGSEGV
, and
SIGBUS
, and terminates the program at appropriate
time, after one of these signals is caught. If you want to have your own
signal handlers for these signals, install handlers
after
VGLInit
().
SIGUSR1
and
SIGUSR2
are internally used by
libvgl
to control screen switching and the mouse
pointer, and are not available to libvgl
client
programs.
HISTORY
The vgl
library appeared in
FreeBSD 3.0.
AUTHORS
Søren Schmidt <sos@FreeBSD.org>